Contrast echocardiography enhances tricuspid but not mitral reguargitation
Bibliographic record
Abstract
Tricuspid regurgitation refers to a systolic leak of blood between the right ventricle and right atrium, across the tricuspid valve. Doppler echocardiographic examination of large numbers of normal individuals has shown that trivial tricuspid regurgitation is extremely common. Measurement of the peak velocity of the regurgitant frequency spectrum on Doppler echocardiography is of considerable clinical importance since it may be used to calculate peak right ventricular and, consequently, peak pulmonary systolic pressure. Doppler recording of the frequency spectrum of a tricuspid regurgitation jet optimally shows a smooth, parabolic, sharply demarcated envelope. In many individuals with trivial tricuspid regurgitation, however, this frequency spectrum is incomplete and its envelope is poorly demarcated. Such inadequate signals do not allow measurement of the spectrum's peak velocity. Like other contrast agents, air-filled microspheres composed of sonicated human serum albumin enhance reflection of Doppler ultrasound and thus have the potential to enhance incomplete tricuspid regurgitation spectra. Furthermore, since sonicated albumin microspheres can cross the pulmonary circulation intact, they have the potential to enhance mitral regurgitation spectra. The purpose of our study was to investigate whether injection of sonicated albumin microspheres enhances incomplete tricuspid and mitral regurgitation frequency spectra to a diagnostic quality. Sonicated albumin microsphere injection enhanced tricuspid regurgitation spectra to optimal quality in 11 of 15 patients (73%). Microsphere injection casused a minor degree of enhancement of the mitral regurgitant spectrum in 1 patient, but did not optimize the spectra in any of 10 patients tested. Saline contrast injection optimally enhance tricuspid regurgitation spectra in all 8 patients in whom was used. Injection of sonicated albumin microsphere caused no change in right ventricular diastolic area or ejection fraction in the 5 patients in whom these variables were measured. Sonicated albumin microspheres caused no adverse effects in this study. There were no changes in heart rate, blood pressure, or respiratory rate following injection of sonicated albumin microspheres. No patient complained of side effects during or after injection. We conclude that sonicated albumin microspheres can be used to enhance incomplete tricuspid regurgitation spectra. This enhancing effect is frequently present even at low doses and is often long-lasting. Use of this contrast agent was safe in this small group of patients, some of whom had end-stage liver disease.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".